ss2tf

% -*- texinfo -*-
% @deftypefn {Function File} {[@var{num}, @var{den}] =} ss2tf (@var{a}, @var{b}, @var{c}, @var{d})
% Conversion from transfer function to state-space.
% The state space system:
% @iftex
% @tex
% $$ \dot x = Ax + Bu $$
% $$ y = Cx + Du $$
% @end tex
% @end iftex
% @ifinfo
% @example
%       .
%       x = Ax + Bu
%       y = Cx + Du
% @end example
% @end ifinfo
%
% is converted to a transfer function:
% @iftex
% @tex
% $$ G(s) = { { \rm num }(s) \over { \rm den }(s) } $$
% @end tex
% @end iftex
% @ifinfo
% @example
%
%                 num(s)
%           G(s)=-------
%                 den(s)
% @end example
% @end ifinfo
%
% used internally in system data structure format manipulations.
% @end deftypefn